Traditional systems, with non-intelligent discharge feeding loads, typically require a large energy storage capacity. In such systems, monitoring of power levels for billing and management purposes is done at relatively long intervals (e.g., 3 to 15 minutes, if not longer). Simple timer based charge windows (e.g., start charging at x time of day, etc.) are typical for any time sensitive charge applications assuming slow rates of charge. Power demand, although charged to customers at the local customer meter, is generally controlled by the utility or Demand Response Provider in 15 minute to 1 hour or longer intervals. Several examples of such non-intelligent systems include icelsystems.com, gridpoint.com, or redflownetworks.com who use 15 minute intervals or ‘dumb’ energy storage under peak shaving control as they being viewed in aggregate from the utility side of the meter.
Such traditional systems result in many disadvantages. For example, traditional systems are not level sensitive in discharge, thereby requiring larger energy storage than is cost effective for a customer to save money. The large size of energy storage required by this approach makes many useful efficiency applications non-economic and prevailing costs of energy storage over the last 100+ years have been significant. Furthermore, traditional systems miss brief intervals where a load is far less than target peak and un-necessarily discharges from an energy storage system into the load without economic or electrical benefit. Furthermore, power delivered on a given phase is not aligned to the power load on the same phase, resulting in upstream mismatches in load and so contributing to inefficiency and higher than necessary fuel consumption.
Thus, a need exists for more intelligent power charge and discharge systems and methods, which more effectively utilize an energy storage system.